In general, people are interested in receiving notifications, especially when the notifications are related to items, content, activities, or events in which the people have shown previous interest or with which they are otherwise associated. For example, a person may be interested in news items associated with a particular keyword or information associated with the release of a product. In order to stay up to date on this information, tools have been developed to allow people to subscribe to email alerts, newsfeeds, and other lists that generally involve a group of items that are ordered chronologically. For example, a news feed may list the most recent news item at the top of a list, while the least recent news item may be at the bottom.
User activity feeds also tend to be chronologically based. A user of a social networking site, for example, may be “connected” to hundreds of friends. Status updates made by friends of the user are often displayed in a feed on the user's home page in chronological order. One problem with seeing feeds in this way is that a feed could have hundreds of items, and the most interesting item is very far down the list. Even if steps are taken to prune seemingly less interesting items from the list, the most interesting item may still be low on the “interesting” list if it a large number of items have been added to the interesting list after the first item was added to the list. Because the addition of new interesting items at the top of the list pushes pre-existing interesting items to lower positions on the list, interesting items eventually get pushed off the list (or at least off the first page of the list that is displayed to the user). When this happens, it may be difficult for a user to “catch up” with the popular items from previous days.
The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualify as prior art merely by virtue of their inclusion in this section.